Eco-friendly plasma cleaning system and method

Abstract

An eco-friendly plasma cleaning system and method are disclosed. The plasma cleaning system comprises a remote plasma device. Here, a precursor having a global warming potential (GWP) of 10,000 or less and an oxygen-containing gas are introduced into the remote plasma device, plasma is generated using the precursor and the oxygen-containing gas in the remote plasma device, and the plasma or radicals corresponding thereto are supplied to a chamber connected to the remote plasma device, so as to clean the chamber.

Description

Eco-friendly plasma cleaning system and method

[0001] The present invention relates to an environmentally friendly plasma cleaning system and method.

[0002] Conventional plasma cleaning systems primarily utilize nitrogen trifluoride (NF3) as a precursor to clean the chamber. However, nitrogen trifluoride (NF3) is a gas with a high global warming potential; although it is not currently regulated, it is scheduled to be regulated soon. Therefore, there is a need for a plasma cleaning system that uses an environmentally friendly gas instead of nitrogen trifluoride (NF3).

[0003] The present invention provides an environmentally friendly plasma cleaning system and method.

[0004] To achieve the above-mentioned purpose, a plasma cleaning system according to one embodiment of the present invention includes a remote plasma device. Here, a precursor having a global warming potential (GWP) of 10,000 or less and an oxygen-containing gas are introduced into the remote plasma device, plasma is generated by using the precursor and the oxygen-containing gas in the remote plasma device, and the plasma or the corresponding radical is supplied to a chamber connected to the remote plasma device to clean the chamber.

[0005] A plasma cleaning system according to another embodiment of the present invention comprises: a spectrometer connected to a waveguide between a remote plasma device that generates plasma using an introduced cleaning gas and a chamber, which detects light generated by a plasma reaction within the remote plasma device during the cleaning process; and a residual gas analyzer that detects residual gas within the chamber during the cleaning process. Here, the degree of cleaning of the chamber is determined through the detection results of the light and the detection results of the residual gas.

[0006] A plasma cleaning method according to one embodiment of the present invention comprises: a step of a remote plasma device receiving an oxygen-containing gas; a step of the remote plasma device receiving a precursor having a global warming potential (GWP) of 10,000 or less after the oxygen-containing gas is introduced; and a step of the remote plasma device generating plasma based on the oxygen-containing gas and the precursor.

[0007]

[0008] The plasma cleaning system according to the present invention can be environmentally friendly because it cleans the chamber using a precursor with a low global warming potential (GWP).

[0009] In addition, the above plasma cleaning system can improve cleaning efficiency by additionally using an oxygen-containing gas.

[0010] FIG. 1 is a drawing illustrating a plasma cleaning system according to one embodiment of the present invention.

[0011] FIG. 2 is a flowchart illustrating a cleaning process according to one embodiment of the present invention.

[0012] FIG. 3 is a drawing illustrating a plasma cleaning system having a monitoring function according to another embodiment of the present invention.

[0013] FIG. 4 is a diagram illustrating a monitoring process at each process step according to an embodiment of the present invention.

[0014] Figure 5 is a diagram showing the change in chamber cleaning thickness.

[0015] Figure 6 is a diagram illustrating the difference in cleaning results according to the power source.

[0016] As used in this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "composed" or "comprising" should not be interpreted as necessarily including all of the various components or steps described in the specification, and should be interpreted as meaning that some of the components or steps may be excluded, or that additional components or steps may be included. Furthermore, terms such as "...part," "module," etc., as used in the specification refer to a unit that processes at least one function or operation, which may be implemented in hardware or software, or a combination of hardware and software.

[0017]

[0018] The present invention relates to a plasma cleaning system and method, wherein a chamber is cleaned using a cleaning gas with a low global warming potential, and the degree of cleaning and the condition of the chamber can be monitored (diagnosed) by analyzing light and by-products generated during the cleaning process.

[0019] Conventional plasma cleaning systems have primarily utilized nitrogen trifluoride (NF3) as a precursor. However, nitrogen trifluoride (NF3) is a gas with a high global warming potential and is not currently subject to regulation, but is scheduled to be regulated soon.

[0020] Accordingly, the plasma cleaning system of the present invention can clean a chamber using a cleaning gas with a low warming potential and monitor the cleaning process within the chamber.

[0021]

[0022] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings.

[0023] FIG. 1 is a drawing illustrating a plasma cleaning system according to one embodiment of the present invention, and FIG. 2 is a flowchart illustrating a cleaning process according to one embodiment of the present invention.

[0024] Referring to FIG. 1, the plasma cleaning system of the present embodiment may include a remote plasma device (100) and a chamber (102). Here, the remote plasma device (100) and the chamber (102) may be connected through a first waveguide (104).

[0025] The remote plasma device (100) generates plasma using the introduced cleaning gas, and can clean the chamber (102) by supplying the plasma, particularly radicals, to the chamber (102) through the first waveguide (104).

[0026] Here, the cleaning gas may be a precursor containing carbon (C) and fluorine (F) or chlorine (Cl) and an oxygen-containing gas. The precursor may be a gas containing carbon (C) and fluorine (F) or chlorine (Cl) and a vaporizable liquid. In this case, the ratio of carbon (C) to fluorine (F) or chlorine (Cl) may be 1 or more : 1, that is, carbon (C) may be greater than fluorine (F) or chlorine (Cl).

[0027] According to one embodiment, the precursor is COF2, CF2OF2 or Carbon-containing gases with a low Global Warming Potential (GWP), such as C3F6O, may be used. The GWP refers to an index that measures how much 1 kg of a specific gas affects global warming compared to 1 kg of carbon dioxide, and the low GWP indicates a value lower than the standard set by climate agreements, for example, a value of 10,000 or less. That is, as a precursor used in the present invention, a gas containing a large amount of fluorine and having a GWP of 10,000 or less may be used. While the GWP of nitrogen trifluoride (NF3), which is commonly used in the past, is 16,800, the GWPs of COF2 and C3F6O are 1 or less and 100, respectively.

[0028] Meanwhile, carbon (C) can form a cleaning inhibition film, such as CF, during a plasma reaction, thereby reducing cleaning efficiency. Therefore, the plasma cleaning system of the present invention may introduce an oxygen-containing gas into the cleaning process to prevent the formation of such a cleaning inhibition film. As the oxygen in the oxygen-containing gas reacts with carbon (C), a cleaning inhibition film may not be formed. Of course, as long as it combines with carbon (C) to prevent the formation of a cleaning inhibition film, the gas introduced together with carbon (C) is not limited to oxygen.

[0029] According to one embodiment, oxygen (O2) or nitrous oxide (N2O), etc., may be used as the oxygen-containing gas.

[0030] At this time, the oxygen-containing gas may be a gas having a binding energy range of 200 kJ / mol to 10,000 kJ / mol with oxygen atoms to prevent gas dissociation prior to plasma generation and the cleaning process, and may be used at 50% or less of the total gas flow rate used in the cleaning process.

[0031] According to one embodiment, a plurality of oxygen-containing gases may be used together in a certain ratio. For example, oxygen (O2) and nitrous oxide (N2O) may be used together during a plasma cleaning process. That is, different types of oxygen-containing gases may be used together for the cleaning process. In this case, the cleaning efficiency may be superior to that when only one oxygen-containing gas is used.

[0032] In summary, the plasma cleaning system of the present invention can clean a chamber (102) using an oxygen-containing gas having a binding energy range of 200 kJ / mol to 10,000 kJ / mol between a precursor containing carbon (C) and fluorine (F) or chlorine (Cl) and having a GWP of 10,000 or less and an oxygen atom. As a result, the plasma cleaning system can be environmentally friendly and have high cleaning efficiency.

[0033]

[0034] Below, we will examine the specific plasma cleaning process.

[0035] Referring to FIG. 2, a diluent gas, such as argon (Ar), can be introduced into a remote plasma device (100) (S200). Here, the diluent gas is a gas for creating a plasma environment and may be an inert gas.

[0036] Next, power can be applied to the remote plasma device (100) (S202). For example, power can be applied to the remote plasma device (100) such that the decomposition rate of the gases is maximized in accordance with the flow rates of the precursor and the oxygen-containing gas. At this time, the power may be higher than the power used in the existing plasma cleaning system.

[0037] Through these steps (S200 and S202), an environment capable of plasma stabilization and radical formation can be created.

[0038] Subsequently, oxygen-containing gas may be introduced into the remote plasma device (100) (S204). For example, oxygen (O2) or nitrous oxide (N2O) may be introduced into the remote plasma device (100), or both oxygen (O2) and nitrous oxide (N2O) may be introduced into the remote plasma device (100). For example, oxygen (O2) and nitrous oxide (N2O) may be introduced into the remote plasma device (100) in a ratio of 7:3.

[0039] Next, a precursor containing carbon (C) and fluorine (F) or chlorine (Cl) is introduced into a remote plasma device (100) (S206), and the oxygen-containing gas can be continuously introduced until the introduction of the precursor is completed.

[0040] In this case, a plasma is formed by an oxygen-containing gas and a precursor, and the plasma, particularly radicals, can be supplied to the chamber (102) through the first waveguide (104).

[0041] Meanwhile, it is also possible to introduce the precursor first and then the oxygen-containing gas later, but in this case, there is a possibility that a cleaning inhibition film may be formed. Therefore, it is preferable to introduce the oxygen-containing gas into the remote plasma device (100) first and then introduce the precursor into the remote plasma device (100).

[0042] In addition, the above steps can be performed with time intervals.

[0043] Subsequently, the dilution gas used to create the plasma environment is stopped to create an environment with a high radical concentration, and then the process pressure of the chamber (102) is adjusted to proceed with the cleaning process (S208 and S210).

[0044] Meanwhile, once the cleaning of the chamber (102) is completed, an additional process may be performed to determine the degree of cleaning or process reproducibility by measuring the voltage or current of the chamber (102).

[0045]

[0046] FIG. 3 is a diagram illustrating a plasma cleaning system having a monitoring function according to another embodiment of the present invention, FIG. 4 is a diagram illustrating a monitoring process at each process step according to one embodiment of the present invention, FIG. 5 is a diagram illustrating a change in chamber cleaning thickness, and FIG. 6 is a diagram illustrating a difference in cleaning results according to a power source.

[0047] Referring to FIG. 3, the plasma cleaning system of the present embodiment may include a remote plasma device (100), a chamber (102), a first waveguide (104), a second waveguide (106), a viewport (300), a spectrometer (302), a voltage / current meter (304), and a residual gas analyzer (306).

[0048] The first waveguide (104) is connected between the remote plasma device (100) and the chamber (102) and is a passage through which plasma flows.

[0049] A viewport (300) is formed in a part of this first waveguide (104), and a spectrometer (OES, 302) can be connected to the viewport (300). As a result, light from a plasma reaction within a remote plasma device (100) can be collected by the spectrometer (302) through the first waveguide (104) and the viewport (300).

[0050] The spectrometer (302) can analyze the collected light to measure the relative amount of chemical species constituting the plasma or the relative decomposition rate of ions and radicals constituting the plasma.

[0051] A voltage / current meter (304) is connected to a part of the first waveguide (104) to measure the voltage or current of the chamber (102), and can monitor the degree of residual thin film accumulated in the chamber (102) by analyzing the measured voltage or current. Accordingly, the plasma cleaning system can determine whether a cleaning process is required before the cleaning process based on the monitoring results, and can determine the degree of cleaning and process reproducibility after the cleaning process.

[0052] The second waveguide (106) is connected to the chamber (102) to discharge residual gas inside the chamber (102). That is, residual gas inside the chamber (102) can be discharged to the outside through the second waveguide (106).

[0053] A residual gas analyzer (306) is connected to a part of the second waveguide (106), and the residual gas analyzer (306) detects residual gas flowing through the second waveguide (106) and can determine the degree of cleaning by analyzing the detected residual gas.

[0054] In particular, the plasma cleaning system can more accurately detect the degree of cleaning and the end point of the cleaning process by utilizing both the analysis results of the spectrometer (302) and the analysis results of the residual gas analyzer (306).

[0055] In addition, the plasma cleaning system can determine whether an appropriate amount of precursor and oxygen-containing gas has been introduced by using the analysis results of the spectrometer (302) and the analysis results of the residual gas analyzer (306).

[0056] According to one embodiment, the plasma cleaning system can determine the ratio of carbon dioxide and fluorine chemical species by using both the analysis results of the spectrometer (302) and the analysis results of the residual gas analyzer (306), and detect the cleaning rate through the ratio.

[0057] According to another embodiment, the plasma cleaning system can monitor carbon and carbon fluoride compounds, which are cleaning and etching interfering substances, using the analysis results of the spectrometer (302) and the analysis results of the residual gas analyzer (306).

[0058]

[0059] Referring to FIG. 4, the overall process monitoring process can be examined. Before the cleaning process, for example, during the deposition process, it is possible to determine whether a cleaning process of the chamber (102) is required based on the voltage or current of the chamber (102) measured by the voltage / current meter (304).

[0060] Subsequently, during the cleaning process of the chamber (102), the plasma cleaning system can detect the degree of progress of the cleaning process and the cleaning endpoint, etc., based on the analysis results of the spectrometer (302) and the analysis results of the residual gas analyzer (306).

[0061] Additionally, the plasma cleaning system can monitor process reproducibility based on the voltage or current of the chamber (102) measured by the voltage / current meter (304) after the cleaning process is completed.

[0062] These processes can be performed repeatedly. As a result, the chamber (102) can be cleaned when cleaning is required, and the process after cleaning is completed can proceed normally.

[0063] Looking at the experimental results, as shown in Fig. 5, it can be confirmed that using the plasma process system of the present invention provides superior cleaning efficiency compared to conventional plasma process systems.

[0064] In addition, as shown in Fig. 6, it can be confirmed that superior cleaning efficiency is obtained when higher power is applied.

[0065]

[0066] Meanwhile, the components of the aforementioned embodiments can be easily identified from a process perspective. That is, each component can be identified as a respective process. Furthermore, the processes of the aforementioned embodiments can be easily identified from the perspective of the components of the device.

[0067] The embodiments of the present invention described above are disclosed for illustrative purposes only, and those skilled in the art with ordinary knowledge of the present invention may make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be considered to fall within the scope of the following claims.

Claims

1. Includes a remote plasma device, but, A plasma cleaning system characterized by introducing a precursor with a global warming potential (GWP) of 10,000 or less and an oxygen-containing gas into the remote plasma device, generating plasma by utilizing the precursor and the oxygen-containing gas in the remote plasma device, and supplying the plasma or the corresponding radical to a chamber connected to the remote plasma device to clean the chamber.

2. A plasma cleaning system according to claim 1, characterized in that a gas containing carbon (C) and fluorine (F) or chlorine (Cl) is used as the precursor.

3. A plasma cleaning system according to claim 2, characterized in that the carbon content in the precursor is higher than the fluorine content.

4. A plasma cleaning system according to claim 1, characterized in that the oxygen-containing gas is a gas having a binding energy range with oxygen atoms of 200 kJ / mol to 10,000 kJ / mol, and is used at 50% or less of the total gas flow rate used in the cleaning process.

5. In paragraph 4, oxygen (O2) and nitrous oxide (N2O) are used together as the oxygen-containing gas, A plasma cleaning system characterized by having a higher content of oxygen (O2) than nitrous oxide (N2O).

6. In paragraph 1, after the dilution gas is introduced into the remote plasma device, the oxygen-containing gas is introduced into the remote plasma device, and after the oxygen-containing gas is introduced, the precursor is introduced into the remote plasma device, wherein A plasma cleaning system characterized by the oxygen-containing gas being continuously introduced until all of the precursor is introduced.

7. In Paragraph 1, A first waveguide connected between the remote plasma device and the chamber; A viewport formed in a part of the first waveguide; A spectrometer connected to the above viewport and collecting light from a plasma reaction within the remote plasma device through the first transducer and the above viewport; A second waveguide connected to the chamber and discharging residual gas inside the chamber to the outside; and It further includes a residual gas analyzer connected to a part of the second waveguide and detecting residual gas flowing from the chamber through the second waveguide, A plasma cleaning system characterized by determining the degree of cleaning through the optical analysis results of the spectrometer and the residual gas analysis results of the residual gas analyzer.

8. A plasma cleaning system according to claim 7, characterized in that the plasma cleaning system determines the ratio of carbon dioxide and fluorine chemical species by utilizing both the optical analysis result of the spectrometer and the residual gas analysis result of the residual gas analyzer, and detects the cleaning rate through the ratio.

9. In Paragraph 1, A first waveguide connected between the remote plasma device and the chamber; and It further includes a voltage / current measuring device formed in a part of the first waveguide, A plasma cleaning system characterized by the above voltage / current measuring device measuring the voltage or current of the chamber, and determining whether cleaning of the chamber is necessary before the cleaning process or monitoring process reproducibility after the cleaning process based on the measurement result.

10. A spectrometer connected to a waveguide connected between a remote plasma device that generates plasma using an injected cleaning gas and a chamber, and which detects light generated by a plasma reaction within the remote plasma device during the cleaning process; and It includes a residual gas analyzer for detecting residual gas in the chamber during the above cleaning process, A plasma cleaning system characterized by determining the degree of cleaning of the chamber through the detection result of the light and the detection result of the residual gas.

11. In Paragraph 10, It further includes a voltage / current measuring device formed in a part of the above waveguide, A plasma cleaning system characterized by the above voltage / current measuring device measuring the voltage or current of the chamber, and determining whether cleaning of the chamber is necessary before the cleaning process or monitoring process reproducibility after the cleaning process based on the measurement result.

12. A step in which a remote plasma device receives an oxygen-containing gas; A step in which the remote plasma device receives a precursor having a global warming potential (GWP) of 10,000 or less after the introduction of the oxygen-containing gas; and A plasma cleaning method characterized by including the step of generating plasma based on the oxygen-containing gas and the precursor using the remote plasma device.

13. In the 12th, the precursor comprises carbon (C) and fluorine (F) or chlorine (Cl), and A plasma cleaning method characterized in that the oxygen-containing gas is a gas having a binding energy range with oxygen atoms of 200 kJ / mol to 10,000 kJ / mol, and is used at 50% or less of the total gas flow rate used in the cleaning process.

14. In Paragraph 12, The above remote plasma device receives a dilution gas, which is an inert gas, before introducing the oxygen-containing gas to create a plasma environment; and A plasma cleaning method characterized by further including the step of stopping the introduction of the dilution gas after the introduction of the precursor.

15. In Paragraph 12, A step of collecting light generated by a plasma reaction within the remote plasma device; A step of detecting residual gas generated when plasma from the remote plasma device is supplied to a chamber and the chamber is cleaned; and A plasma cleaning method characterized by further including the step of determining the degree of cleaning or the cleaning endpoint of the chamber through the analysis results of the collected light and the analysis results of the detected residual gas.

16. In Paragraph 12, A step of measuring the voltage or current of a chamber connected to the remote plasma device before the cleaning process; and A plasma cleaning method characterized by further including a step of determining whether a cleaning process of the chamber is necessary through the above measurement results.

17. In Paragraph 12, A step of detecting residual gas in a chamber connected to the remote plasma device after the cleaning process; and A plasma cleaning method characterized by further including the step of analyzing the detected residual gas to determine the process reproducibility of the chamber.

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